From the DDE main page you also have links to further information about all the supported data formats.

The internal web server is not the only way to publish information on the web: DDE is implemented as a WSGI application, and can be deployed as CGI, FastCGI, SCGI, mod_wsgi and pretty much any other way you can think of.

Explore JavaScript integration

Load the file ./complete.html into a browser while the DDE server is running and type the first few letters of a package name: after a short moment a popup should appear suggesting possible completions.

Have a look at the source code to see how simple it can be to use DDE to add autocompletion to web forms.